The present disclosure relates to a press die that is used to form, for example, a fuel cell separator.
A generally known separator that is used for a fuel cell includes a plate made of a hard metal material, such as titanium, in which concavo-convex portions through which hydrogen, oxygen, etc., are allowed to flow are formed.
Japanese Laid-Open Patent Publication No. 2015-131344 discloses a press die apparatus that has a press die to form the thus structured separator. This press die apparatus includes a lower die that has a concavo-convex upper surface serving as a forming surface and an upper die that has a concavo-convex lower surface corresponding to the forming surface of the lower die. The upper die is disposed so that it can move closer to and away from the lower die. The upper die is moved toward the lower die in a state in which a workpiece plate is placed on the forming surface of the lower die, and, as a result, the workpiece plate is pressed between the forming surfaces of both dies to form concavo-convex portions.
The conventional upper and lower dies disclosed by Japanese Laid-Open Patent Publication No. 2015-131344 each have a base and a plurality of quadrangular-prism-shaped die members that are disposed on the base and that are fitted in a frame in a mutually aligned state. The forming surface is defined by forward end surfaces of the die members.